Sheet guide apparatus

ABSTRACT

A guide arrangement for guiding sheet material through a developer unit over and in contact with a roller, the surface of which is wetted with a liquid developer solution, includes a plurality of fine, filament-like guide wires strung taut across the roller in the direction of movement of the sheet material. The wires prevent the sheet material from becoming wrapped about the roller member.

United States Patent [151 3,707,328 Robertson [451 Dec. 26, 1972 s41SHEET GUIDE APPARATUS 3,386,730 6/1968 Hyosaka "ass/110 x [721 fi MFOREIGN PATENTS 0R APPLICATIONS rospect,

1 4 19 B [73] Assignee: Addressograph-Multigraph Cor- 86 l 2/ 61 Greatmam 355,110 poration, Mount Prospect, 11]. primary Examiner lohn Oran[22] Filed: Oct. 2, 1970 Assistant Examiner-Alan A. Mathews At 1 .G ldt211 App]. No.: 77,669 L S em [57] ABSTRACT [52] U.S.C1 ..355/106,355/110, 95/94 R A guide arrangement for guiding sheet material througha developer i overand in Contact a [5 1 0 55/ roller, the surface ofwhich is wetted with a liquid 355/64 95/89 94 R developer solution,includes a plurality of fine, fila- 5 t ment-like guide wires strungtaut across the roller in 6] Re erences cued the direction of movementof the sheet material. The UNITED STATES PATENTS wires prevent the sheetmaterial from becoming wrapped about the roller member. 3,484,16812/1969 Toby ..355/ll0X 1,900,878 3/1933 Hopkins ..355/64 2 Claims, 3Drawing Figures BACKGROUND OF THE INVENTION This invention relatesgenerally to direct contact type copying machines including developerunits wherein copy sheets have applied thereto, by means of a rollermember, a quantity of developer liquid, and more particularly to meansfor guiding the copy sheets safely through the developer unit.

In direct contact copy machines, such as, for example, of the type shownand described in U.S. Pat. No. 3,484,168, assigned to the same assignee,wherein a superimposed copy sheet and original tracing are exposed andsubsequently separated, and the copy sheet continues to be transportedthrough a developer unit whereat a liquid developer solution is appliedto the copy sheet as the latter is carried over a rotating applicatorroller, there exists the possibility that the copy sheet, rather thanmerely passing over the roller, will adhere to the wetted roller surfaceand become wrapped thereabout. Also, if the original and copy sheet arenot separated after passing through the exposure station, there is apossibility that the original will become wrapped about the liquidapplicator roller. If the above occurs, the copy sheet and originalcould be damaged. Also, it becomes a difflcult and time consuming matterto easily release the wrapped sheets from the roller.

SUMMARY OF THE INVENTION paratus of the present invention includes aplurality of extremely fine, filament-like guide wires having a diameterof 0.004 inches or less, preferably about 0.002 inches, strung tautacross the wetted applicator roller between the entrance and exit of thedeveloper unit in a copying machine in contact with the surface of saidroller. The wires are in spaced relation to each other along the axis ofthe roller. Each of the guide wires is tensioned at least at one end sothat the rotational movement of the applicator roller is impededminimally by the wires and so the wires are able to ac-.

commodate any irregularities in the surface of the roller withoutbreaking. The wetted surface of the roller minimizes the frictionbetween the wires and the roller surface.

Copy sheets entering the developer unit are guided along the wires overthe surface of the developer applicator roller for development and areprevented by the wires from'becoming wrapped about the roller. The wiresprovide little, if any, interference with the developing process.

DESCRIPTION OF THE DRAWINGS A better understanding of the presentinvention and its organization and construction may be had by referringto the description below in conjunction with the accompanying drawings,wherein:

FIG. 1 is a fragmentary, sectional view of a copying machine including adeveloper arrangement employing a liquid. applicator roller andincluding sheet guide apparatus according to the invention;

FIG. 2 is an enlarged, fragmentary view of the developer arrangement ofthe copying machine of FIG. 1 illustrating in greater detail the sheetguide apparatus of the invention; and

' FIG. 3 is a fragmentary, plan view of the developer apparatus of FIG.2 taken along the line 33.

DETAILED DESCRIPTION Referring now to FIG. 1 of the drawings there isillustrated therein an'automatic copying machine 10 similar to the typeshown and described in U.S. Pat. No. 3,484,168, embodying the featuresof the present invention.

The copying machine 10 includes a rotating transparent drum 12containing a light source in the form of a lamp 14 to which asuperimposed original 16 and copy sheet 18 are fed from feed board 20along a path 22 beneath guide member 23. The superimposed copy sheet andoriginal are fed past the light source 14 to expose the copy sheetthrough the cooperation of the rotating drum 12 and a flexible guidingassembly, indicated generally as 24, serving to hold the superimposedsheets in engagement with drum 12 through a portion of the path. Theflexible guiding assembly 24 includes a plurality of laterally spacedflexible, endless belts 26 supported by transparent drum l2 and by aplurality of rollers 28, 30, 32, 34 and 36. The superimposed originaland copy sheet are nipped between the rotating drum 12 and the endlessbelts 26 and rotate with the drum past the light source 14 where thecopy is exposed by light passing through transparent or translucentareas of the original.

After exposure of the copy sheet 18, the superimposed original and copysheet enter the separating sta tion 38 where they are separated fromeach other by a pair of vacuum chests 40, 42, each including aperforated plate respectively adjacent the original and copy sheet. Theforce provided by the vacuum chest 40 separates the original from thecopy sheet and causes it to be moved into engagement with a guide 44,serving to channel the original between a pair of original deliveryrollers to a tray (not shown) disposed at the front of the machine.

The vacuum chest 42 holds the copy sheet in engagement with the endlessbelts 26 and the sheet is moved between a guide roller 50 and belts 26carried along roller 36 toward a curved guiding structure 52. From therethe sheet is carried between guide plate 54 and guide plate 57 formingan entrance 55 to the developer unit 56. The exposed copy sheet 18 ispassed through entrance 55 of the developer unit into the nip 59 of anapplicator roller 58 and a pressure roller 60, where it is wetted with adeveloper liquid contained in a tray 62, which liquid is applied to thesurface of the applicator roller 58 by means of a fountain roller 64.

The copy sheet 18 is guided from the developer unit 56 by upper guideplate 66 and guide comb -68, forming exit 70 of the developer unit,through a pair of copy sheet delivery rollers 72, 74, and along a guide76 to the copy receiving tray 78 disposed at the front of the copymachine. I

On some occasions during the developing of the copy sheets passingthrough developer unit 56, a copy sheet will adhere to the wettedapplicator roller 58. When the latter occurs the copy sheet b'ecomeswrapped about the roller 58 and continues'to rotate thereaboutindefinitely. This wrapping of the copy sheet about the roller 58 coulddamage the copy sheet, and make it impossible to process subsequentcopies through the developer unit until the sheet is removed.Furthermore, it is difficult and time consuming to free the wrapped copysheet from the roller. Y

In, addition to the above, occasionally an original document fails toseparate from a copy sheet in the separator station 38. When thishappens both the original and copy sheet are carried into the developerunit. Since the thickness of the two sheets is greater than the copysheet alone, and since the original document is usually of a relativelylight weight and rather flimsy, as in the case of translucent tracings,the original document which is delivered to the developer unit incontacting relation with the applicator roller 58, adheres to the wettedroller surface and .becomes wrapped about the roller. The latter notonly presents the problem of having to dismantle the machine to free thewrapped original from the roller, but may result in the destruction ofan original of which there may only be a single copy. a To prevent theabove situations from occurring, there has been provided in thedeveloper unit 56 of the copying machine 10, a guide arrangement 80,best seen in FIGS. 2 and 3, v

. The guide arrangement 80 includes a plurality of extremely fine,filament-like wires 82, each having a diameter less-than 0.004 inchesand preferably about The developer unit 56' of the copying machinedescribed heretofore includes a metering system (not shown) forregulating the amount of developer liquid applied to a copy sheetpassing between the applicator and pressure rollers 58 and 60,respectively. In fact, the amount of developer liquid applied by theapplicator roller 58 is less than 3.0 grams per square meter andpreferably between 0.5 and 1.0 grams. A more complete description of theconstruction and operation of the metering system maybe had by referringto copending Pat. application, Ser. No. 831,399 filed June herein is notrestricted to a metallic member, but refers forces applied thereagainstby the action of the pressure and applicator rollers, and the movingsheet material.

The guide wires 82 positively prevent a copy sheet or original tracingwhich might not have been separated, from wrapping about the wettedapplicator roller. The wires guide the sheet across the applicatorroller 58 and provide little, if any, interference with the developmentof the copy sheet.

9,1969, which is a continuation-impart application of earlier filed-US.patent application, Ser. No. 606,332, filed Dec. 30,1966. Y

Becauseso little developer liquid is applied to a-copy sheet in thecopying machine l0,.one would predict that the guide wires used to guidethe-copy sheet safely through the developer zone, would leave striationsor marks on the developed copy sheetafter development. Surprisingly,this does not occur. It is believed that the combination of the fine,filament-like wires and the use of developer liquid of a properconsistency compensates for any tendency to leave striations on thedeveloped sheet. As the copy sheet passes through the developer stationbetween applicator and pressure rollers 58, 60, any striations formed bythe guide wires quickly disappear due to the flow of developer liquidthereinto. Upon exiting from the machine, the striations are notevident, and the copy sheet is uniformly developed.

The particular mounting arrangement for the guide wires 82 shown inFIGS. 1-3 of the drawings is illustrated in FIG. 2. One end 84 of eachof the guide wires is attached to a mounting post 86 which can beaffixed to an existing wall or the like structure of the developer unit.The other end 88 of the wire 82 is attached to a resilient member,herein taking the'form of a coiled spring 90 which in turn is connectedto a mounting bracket 92, also affixed to an existing structure in thedeveloper unit. The spring 90 provides the tension required for the wire82 across applicator roller 58, as well as being a safety release toprevent the wire from snapping due to excessive forces appliedthereagainst.

The guide wire arrangement according to the invention is a positive butsimple means to prevent copy sheets and/or original tracings frombecoming wrapped about the liquid applicator roller in a copying machineof thetype described. The guide arrangement is very effective and needslittle, if any, maintenance. In the event a wire of the guidearrangement should require replacement, it is a simple matter to releasethe wire from its mountings and affix a new wire in its place.

copy of an original document on a copy sheet, including an exposurestation whereat a superimposed original and copy sheet are illuminatedto create an image of the former on the latter, a separating stationwhereat the original and copy sheet are separated, and a developingstation including a developer unit comprising an entrance and an exitand having therebetween an applicator roller, the surface of which iswetted with a liquid developer solution for application to the surfaceof a copy sheet transported thereover in contact therewith, and

a pressure roller mounted in driving engagement with said applicatorroller, sheet guiding means for guiding sheet material in eluding saidcopy sheet and original documents which have failed to be separated fromsaid copy sheet, safely over said applicator roller while preventing thewrapping of said sheet material about said wetted applicator roller,said sheet guiding means including a plurality of fine guide wiresstrung taut between the entrance and the exit of said developer unitover and in contact with said roller member and between said applicatorand pressure rollers, said wires further being spaced from each otheraxially along said applicator roller over the length thereof so as toaccommodate sheets of varying widths, wherein 'each of said guide wiresis of a diameter of less than 0.004 inches.

2. In a direct contact copying machine for making a copy of an originaldocument on a copy sheet, including an exposure station whereat asuperimposed original and copy sheet are illuminated to create an imageof the original on the copy sheet, and a developing station including aliquid developer unit comprising an entrance and an exit through whichsaid copy sheet is passed for development, having a supply of liquiddeveloper solution, an applicator roller for use in applying apredetermined amount of developer liquid to said copy sheet passingthrough said unit, and metering means for metering a predeterminedquantity of developer liquid from said supply to said applicator roller,said roller applying less than 3.0 grams per square meter of liquid tosaid copy sheet, wherein the improvement comprises sheet guiding meansfor guiding the original document and the copy sheet safely through saiddeveloper unit in contacting relation with said applicator roller whilepreventing the wrapping of either or both of said document and copysheet about said roller, said sheet guiding means including a pluralityof fine, filament-like guide members extending between the entrance andexit of said developer unit, over and in contact with said rollermember, said guide members comprising wires, each having a diameterlessthan 0.004 inches, strung taut between the entrance and the exit ofsaid developer unit, wherein each said wire is held at one end by aspring member to provide a tension to said wire while avoiding breakagethereof due to forces applied thereagainst.

1. In a direct contact copying machine for making a copy of an originaldocument on a copy sheet, including an exposure station whereat asuperimposed original and copy sheet are illuminated to create an imageof the former on the latter, a separating station whereat the originaland copy sheet are separated, and a developing station including adeveloper unit comprising an entrance and an exit and havingtherebetween an applicator roller, the surface of which is wetted with aliquid developer solution for application to the surface of a copy sheettransported thereover in contact therewith, and a pressure rollermounted in driving engagement with said applicator roller, sheet guidingmeans for guiding sheet material including said copy sheet and originaldocuments which have failed to be separated from said copy sheet, safelyover said applicator roller while preventing the wrapping of said sheetmaterial about said wetted applicator roller, said sheet guiding meansincluding a plurality of fine guide wires strung taut between theentrance and the exit of said developer unit over and in contact withsaid roller member and between said applicator and pressure rollers,said wires further being spaced from each other axially along saidapplicator roller over the length thereof so as to accommodate sheets ofvarying widths, wherein each of said guide wires is of a diameter ofless than 0.004 inches.
 2. In a direct contact copying machine formaking a copy of an original document on a copy sheet, including anexposure station whereat a superimposed original and copy sheet areilluminated to create an image of the original on the copy sheet, and adeveloping station including a liquid developer unit comprising anentrance and an exit through which said copy sheet is passed fordevelopment, having a supply of liquid developer solution, an applicatorroller for use in applying a predetermined amount of developer liquid tosaid copy sheet passing through said unit, and metering means formetering a predetermined quantity of developer liquid from said supplyto said applicator roller, said roller applying less than 3.0 grams persquare meter of liquid to said copy sheet, wherein the improvementcomprises sheet guiding means for guiding the original document and thecopy sheet safely through said developer unit in contacting relationwith said appLicator roller while preventing the wrapping of either orboth of said document and copy sheet about said roller, said sheetguiding means including a plurality of fine, filament-like guide membersextending between the entrance and exit of said developer unit, over andin contact with said roller member, said guide members comprising wires,each having a diameter less than 0.004 inches, strung taut between theentrance and the exit of said developer unit, wherein each said wire isheld at one end by a spring member to provide a tension to said wirewhile avoiding breakage thereof due to forces applied thereagainst.